National Instruments NI PCI-5911 - Manual (Page 41)

Glossary
© National Instruments Corporation G-3 NI PCI-5911 User Manual
clock hardware component that controls timing for reading from or writing to
groups
CMRR common-mode rejection ratio—a measure of an instrument’s ability to
reject interference from a common-mode signal, usually expressed in
decibels (dB)
counter/timer a circuit that counts external pulses or clock pulses (timing)
coupling the manner in which a signal is connected from one location to another
D
dB decibel—the unit for expressing a logarithmic measure of the ratio of
two signal levels: dB = 20log10 V1/V2, for signals in volts
DC direct current
default setting a default parameter value recorded in the driver. In many cases, the default
input of a control is a certain value (often 0) that means use the current
default setting.
device A plug-in data acquisition device, card, or pad that can contain multiple
channels and conversion devices. Plug-in devices, PCMCIA cards, and
devices such as the DAQPad-1200, which connects to your computer
parallel port, are all examples of DAQ devices. SCXI modules are distinct
from devices, with the exception of the SCXI-1200, which is a hybrid. The
NI 5911 is an example of a device.
differential input an analog input consisting of two terminals, both of which are isolated from
computer ground, whose difference is measured
double insulated a device that contains the necessary insulating structures to provide electric
shock protection without the requirement of a safety ground connection
drivers software that controls a specific hardware instrument